A semiconductor device having high reliability, in which TFTs with appropriate
structures for the circuit functions are arranged, is provided. Gate insulating
films (115) and (116) of a driver TFT are designed thinner than a
gate insulating film (117) of a pixel TFT in a semiconductor device having
a driver circuit and a pixel section on the same substrate. In addition, the gate
insulating films (115) and (116) of the driver TFT and a dielectric
(118) of a storage capacitor are formed at the same time, so that the dielectric
(118) may be extremely thin, and a large capacity can be secured.
